A methodology for designing thermodynamic energy conversion systems in industrial mass/heat integration problems based on MILP models

摘要

The integration of thermodynamic systems in industrial processes can help increasing the energy recovery and provide more integration opportunities. However, designing such technologies in a simultaneous mass and heat integration is a large-scale and complex problem. Indeed, the heat requirements created by the mass allocation network are unknown prior to the whole design. Besides, designing sequentially the mass allocation network (MAN) and the heat exchanger network (HEN) can lead to suboptimal solutions. This paper proposes a three-step methodology based on mixed-integer-linearprogramming (MILP) models to evaluate economically suitable technologies, reducing strongly the computational time. After a preliminary step, a first MILP model evaluates economically a great number of technologies simultaneously. In this model, the simplified total cost, including thermodynamic systems capital costs, is minimized. Then, the best thermodynamic systems candidates are identified and used in a second MILP solving the larger problem including the simultaneous MAN and HEN design. The performances of the methodology are assessed on an ammonia recovery case study: 3 economically relevant technologies among 74 are selected in a few seconds. Then, the MAHEN (mass allocation and heat exchange network) is designed with these technologies, showing a decrease of total annualized cost of 3.6%. (C) 2019 Elsevier Ltd. All rights reserved.